Flexor digitorum profundus​

Flexor digitorum profundus Definition

What is Flexor digitorum profundus? The Flexor digitorum profundus is the deep muscle in the hand and foot that helps bend the fingers and toes. The muscle belongs to the deep group of Antebrachial muscle in the anterior compartment. The Flexor digitorum profundus muscle has its origin in:

Interosseous membrane’s ulnar side

Posterior ulnar border

Coronoid process’ medial side

Medial and anterior surfaces of the ulna, along the ulnar shaft’s entire length

It is also referred to as Musculus flexor digitorum profundus in Latin and as Muscle fléchisseur profond des doigts in French. Its name comes from the Latin terms “flectere” which means “to bend” and “digitus” which stands for “pointing thing”. In Latin, the term “profundus” stands for “deep”.

Flexor digitorum profundus Insertion

The muscle has its point of insertion in the anterior surface of the base of fingers’ distal phalanges – the common muscle group for the little, middle and ring fingers, with many links between the 3 tendons.

Flexor digitorum profundus Function

This muscle is involved in flexing all the joints of the digits and wrists.

Flexor digitorum profundus Innervation

It is supplied by the ulnar and median nerves T1 and C8. From proximal to distal, this muscle gets its blood supply from the following areas:

Ulnar artery’s small muscular branches

Posterior and anterior interosseous arteries

Posterior ulnar recurrent artery

Ulnar collateral arteries

​The proper and the common palmar digital arteries provide the distal tendons of this muscle with blood supply. The deep palmar arch, thorough the palmar metacarpal arteries, also supply blood to the muscle’s distal tendons.

Flexor digitorum profundus Tendon

The Flexor digitorum profundus tendon, which helps flex the DIP joint, affixes to the base of the distal phalanx. Disinsertion of the tendon can occur in case of a blunt trauma. In such cases, physical Flexor digitorum profundus test shows incapability of distal phalanx flexion. Radiograph might show a small bone chip. There can be indications of referral for surgery. In athletes, avulsion injuries of this tendon are common.

Flexor digitorum profundus Injury

Cases of Flexor digitorum profundus injury are common. The complications that are experienced most frequently include:

Stiffness of finger joints

Adhesion formation

Flexor digitorum profundus rupture of tendon, with rupture risks being the highest between the 7th and 10th day after repair

Most of these tendon injuries occur due to accidental trauma. Other typical causes include:

Suture failure during surgical repair

Local inflammation after operation

Recent or prior infection of the tendons

Tendon sheath adhesions or scar tissue formation due to prior surgery

Inflammatory or metabolic disorders, such as rheumatoid arthritis or infection, which can increase rupture risks by weakening the integrity of tendons